Roof and wall support is vital in mining and tunnelling operations. Mine and tunnel walls and roofs consist of rock strata, which must be reinforced to prevent the possibility of collapse. Rock bolts are widely used for consolidating the rock strata.
In conventional strata support systems, a hole is drilled into the rock by a drill rod, which is then removed and a rock bolt is then installed in the drilled hole and secured in place typically using a resin or cement based grout.
To improve this process, self drilling rock bolts have been proposed whereby the bolt is also used as the drill rod. As such, with a self drilling rock bolt, the hole can be drilled and the bolt installed in a single pass.
Whilst self drilling rock bolts provide the opportunity to substantially improve installation times of rock bolts, they have not been widely used.
Rock bolts are furthermore at times not anchoring in the predrilled hole as well as can be expected.